The present invention relates to a clutch cup for a centrifugal clutch of a hand-held working tool, especially a trimmer, driven by an internal combustion engine whereby the clutch cup is comprised of a clutch drum, a hub coaxially fastened thereto with a bearing bushing arranged therein and with a coaxially fastened receiving element for receiving the end of a drive shaft.
Hand-held working tools driven by a internal combustion engine often include a centrifugal clutch by which the driven working tool at low rpm of the internal combustion engine is turned off and with increasing rpm is automatically switched on due to the centrifugal forces. Thus, the operation of the working tool is simplified and operational safety increased.
In hand-held working tools, especially trimmers, the centrifugal member of the centrifugal clutch is fixedly connected to the crank shaft of the combustion engine while the clutch cup that encloses the centrifugal member is rotatably supported on the crankshaft end in a bearing bushing or in a separate clutch housing.
In the case of support on the crankshaft, the bearing bushing is inserted into the hub of the clutch cup. The connection bearing bushing/hub is mechanically greatly stressed so that securing against loosening and axial movement of the bearing bushing is required.
In order to axially secure the bearing bushing in the hub, the inner side of the clutch drum is provided with a disc welded thereto having an inner diameter that is slightly smaller than the outer diameter of the bearing bushing. This type of axial securing is complicated because an additional part and a welding connection as well as an additional working step are required.
It is therefore an object of the present invention to provide a reliable and inexpensive axial securing of a bearing bushing inserted into the hub of the clutch cup of a centrifugal clutch.